Never heard of KPK, listened to some of their ukes on yt, mostly acacia, but one of the tenor vids might have been mahogany, it had great sustain, sounded good. Their acacias also sounded better than most affordable ukes I've heard, though the mahogany might be better than the acacia, I'd have to hear them side by side. They look like much more upscale ukes, so I think you got a great value there. How did you find out about them?
So this is your first uke? I just went through the same thing a couple weeks ago, when waiting for my first uke. It was more intense than I expected. If you want, and it's UPS, you can have them "hold it for pickup", and go down to the local HUB as soon as it arrives (usually 8am) and get it before it goes out on a truck for the day. I did this because of the winter shipping issue, I was afraid the temp change of a truck in the sun (I'm in california and it was in the 60s that week, and the uke had previously spent two days below freezing), and banging around all day in the truck might cause finish cracks or worse. In retrospect, it was probably unnecessary and irrational, but that's what happens when waiting for a uke.